动态光散射实验

动态光散射技术是测量纳米及亚微米颗粒粒径的有效方法．本文介绍了动态光散射实验的原理、实验装置及方法，并测量了粒径为85nm的聚苯乙烯水溶液的粒径，分析了实验产生误差的原因．     

A Comparative Study on Dynamic and Static Sparsity Patterns in Parallel Sparse Approximate Inverse Preconditioning

Sparse approximate inverse (SAI) techniques have recently emerged as a new class of parallel preconditioning techniques for solving large sparse linear systems on high performance computers. The choice of the sparsity pattern of the SAI matrix is probably the most important step in constructing an SAI preconditioner. Both dynamic and static sparsity pattern selection approaches have been proposed by researchers. Through a few numerical experiments, we conduct a comparable study on the properties and performance of the SAI preconditioners using the different sparsity patterns for solving some sparse linear systems. This revised version was published online in July 2006 with corrections to the Cover Date.     

OXIDATION OF TiAl,Ni AND Fe IN A DYNAMIC ENVIRONMENTAL SEM

IntroductionInmaterialscience,differentmicrostructuresofthesamematerialsmayinducediversebehaviorsanddifferentcharacteristics.Westwood(1988)showed,asanexample,thatthetreatmentofaluminumsurfacewithcommercialphosphoricacidproducedmechanicallyinterlockedoxide搘hiskers?approximately10nmindiameterand400nminlength,whichmechanicallyinterlocked.Thismicro-structurecankeepsuchaconglomeratebondedoverconsiderablerangesofstressandtemperature.Inahumidatmosphere,especiallythatcontainingchlorine,however,suchox…     

《左传》人物祸福预言类型考论

将<左传>中所记载的人物祸福预言,作出分类与考论,将其分为形貌,言语行为、梦境、卜筮、灾异、天象、歌谣(谶语)六类,并通过此类预言对其所具有的社会思想价值作出分析与评论.     

Stability of Markovian structure observed in high frequency foreign exchange data

Contrary to the common sense in economics and financial engineering, price fluctuations at very fine level of motion exhibit various evidences against the efficient market hypothesis. We attempt to investigate this issue by studying extensive amount of foreign currency exchange data for over five years at the finest level of resolution. We specifically focus on the proposed stability in binomial conditional probabilities originally found in much smaller examples of financial time series. In order to handle very large data, we have written an efficient program in C that automatically generates those conditional probabilities. It is found that the stability is maintained for extremely large time duration that covers almost the entire period. Based on the length of conditions for which the conditional probabilities are distinguishable each other, we identify the length of memory being less than 3 movements.     

陈骥《文则》的现代修辞观

陈骏的《文则》是中国历史上第一部谈及文法修辞的专著，其价值是多方面的，本文从陈骏创作实践中运用多种积极辞格阐述相关的修辞理论，以评价他的积极修辞观；《文则》“虽以事出创造，不无瑕疵”，但论及了语法、句法、辞格、文章、风格、文体等多方面内容，初步建立了大修辞学体系，体现了现代修辞学界所倡导的广义修辞观；陈骏虽是对《诗》《书》《礼》《易》《春秋》等静态书面语言的考察，但用动态的辩证的眼光提出了不少真知灼见，体现了动态的辩证的修辞观。     

BP人工神经网络用于除草剂活性预测

采用AMI方法研究了10种新型的磺酰脲类除草剂的电子结构，并以原子的Mulliken净电荷和除草剂在不同浓度(100，10mg／L)下对油菜、稗草两种作物的根、茎部位的抑制率为训练样本集。构造并训练得到具有活性预测能力的BP神经网络．结果表明，该BP网络不仅能对训练样本很好拟合。亦能对未知化合物的活性作出很好的预测．     

Functional Nanostructures and Dynamic Materials through Self-Organization

1 Results Supramolecular chemistry is actively exploring systems undergoing self-organization.The design of molecular information controlled,“programmed“and functional self-organizing systems provides an original approach to nanoscience and nanotechnology.The spontaneous but controlled generation of well-defined,functional molecular and supramolecular architectures of nanometric size through self-organization represents a means of performing programmed engineering and processing of functional nanostruct...     

重力场与静电场特点的比较

“场”是一种客观存在的物质，但由于“场”具有不易直接感受的特殊存在形态，同学们对“场”的物质性的理解不够深刻，解决“场”的相关问题时也感到棘手．笔者就高中阶段最典型的两种场——“重力场”和“静电场”的力学性质与能量特点进行比较，使同学们对“场”的概念有更深刻的认识．     

冲击载荷下剪切断裂研究

利用Hopkinson压杆技术对单边平行双裂纹试样倒向加载，在较大的加载率范围，对Ti6Al4V钛合金和40CrNiMoA两种材料的动态剪切断裂行为进行了研究．实验结果表明：存在两类韧性剪切断裂模式，即常规的韧性剪切型断裂和绝热剪切断裂．常规剪切型断裂模式的断裂韧性KⅡd随加载率的提高而增大，而绝热剪切型的断裂韧性KⅡd则随加载率的提高而减小，并且，当加载率增大至某一临界值时，常规的韧性剪切断裂模式将转变为绝热剪切断裂破坏模式．